3 kubels you say interesting thats 240*3 MP so im guessing they only have strummis out to cap points , did you try spreading out your 3 rifle mans rear echs so you can cap multiple places or decap his cutoff he cant engae at all places is there a replay u can upload ?
try Mehcanized commander you cant get a Military truck out at 1CP.
Didn't upload a replay because I was looking more for general advice on countering it, as opposed to that particular game, but if I get a spare moment I'll upload it!
If you wanna see a more successful Kubel spam strategy, look at Aerohank versus Breaking Brad in the replay forum.
The lack of capping power isn't a problem for this build because the Kubels also prevent the US player from capping. If you spread out and run away from the Kubels they just split the Kubels and use them to solo the riflemen - failure to retreat or run into a build in this case generally means death. They're also fast enough that if you try to flank again they can regroup the Kubels and a full circle practically.
Here are some examples of it:
http://www.coh2.org/replay/24195/hashtag-esports (against US)
http://www.coh2.org/replay/24184/esports (against soviets)
AT Grenades work fine as a counter but I'd rather not always play as Rifle Company. I don't have Mech Company.